<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    .yellowgreenbox {
      width: 60px;
      height: 60px;
      border-radius: 3px;
      background-color: yellowgreen;
    }

    #box {
      position: relative;
      border: 1px solid black;
      width: 500px;
      height: 400px;
    }
  </style>
</head>
<body style="height: 2000px">

  <div id="box">
    <div v-drag class="yellowgreenbox">拖走了</div>
  </div>

  <script src="./js/vue.js"></script>
  <script src="./js/myDirectives.js"></script>
  <script>
    let a = new Vue({
      el: "#box",
      data: {}
    })
  </script>
</body>
</html>